we need to upgrade to resin pro 4.0.15 (currently we have resin pro 3.1.6) and we are facing ?Session replication? issue in INT environment where we have resin pro 4.0.15 installed on both servers.

The problem appeared that if we run app on both servers it looks like the session is stored just on both but whenever request is redirected to the second server during the session then it fails to keep session alive and throws a message that the ?session is expired or user never logged in?.

However if we run the app on one (1st or 2nd) server we never face that issue.

My understanding what happened is that the session data can?t be reached or mapped on the second server. That is why when the request goes to the second server it always returns with ?Session expired? message. Even though that the second server keeps the session alive it won?t validate it and always returns ?session expired? message.

It doesn?t happen for resin 3 though and we didn?t change the CookieSetterFilter.java, CookieSetterFilterMBean.java that are responsible for signing cookie to particular domain.

I have attached resin.conf , resin.sh that we use for startup.

I also attached logs from 1st resin server, 2nd resin server, log from our app on 1st server, log for our app on 2nd server and Summary of all logs file to review.